How to test BT TRIAC Good test with Bad

 How to test BT TRIAC Good test with Bad

Today i will show you how to test bt triac easy to understand bt136, bt134 test good transistor with bed transistor, simple and easy electronics projects make at home.

Triac Testing Digital Multimeter. BT136 Triac Test can be triggered by applying either a positive or negative voltage to the gate (an SCR requires a positive voltage). Once triggered, SCRs and TRIACs continue to conduct, even if the gate current ceases, until the main current drops below a certain level called the holding current.

  TRIAC:---

A TRIAC (triode for alternating current; also bidirectional triode thyristor or bilateral triode thyristor[1]) is a three terminal electronic component that conducts current in either direction when triggered. The term TRIAC is a genericized trademark.

TRIACs are a subset of thyristors (analogous to a relay in that a small voltage and current can control a much larger voltage and current) and are related to silicon controlled rectifiers (SCRs). TRIACs differ from SCRs in that they allow current flow in both directions, whereas an SCR can only conduct current in a single direction. Most TRIACs can be triggered by applying either a positive or negative voltage to the gate (an SCR requires a positive voltage). Once triggered, SCRs and TRIACs continue to conduct, even if the gate current ceases, until the main current drops below a certain level called the holding current.

The bidirectionality of TRIACs makes them convenient switches for alternating-current (AC). In addition, applying a trigger at a controlled phase angle of the AC in the main circuit allows control of the average current flowing into a load (phase control). This is commonly used to control the speed of a universal motor, dimming lamps, and controlling electric heaters. TRIACs are bipolar devices.

DIAC:-The DIAC (diode for alternating current) is a diode that conducts electrical current only after its breakover voltage, VBO, has been reached momentarily. Three, four, and five layer structures may be used [1] Behavior is similar to the voltage breakdown of a triac without a gate terminal.

When breakdown occurs, internal positive feedback (impact ionization or two transistor feedback) ensures that the diode enters a region of negative dynamic resistance, leading to a sharp increase in current through the diode and a decrease in the voltage drop across it (typically full switch -on takes a few hundred nanoseconds to microseconds). The diode remains in conduction until the current through it drops below a value characteristic of the device, called the holding current, IH. Below this threshold, the diode switches back to its high-resistance, non-conducting state. This behavior is bi-directional, meaning typically the same for both directions of current.

Most DIACs have a three-layer structure with breakover voltage of approximately 30 V and an on voltage of less than 3 V. Their behavior is analogous to the striking and extinction voltages of a neon lamp, but it can be more repeatable and takes place at a lower voltages.

DIACs are also called "symmetrical trigger diodes" due to the symmetry of their characteristic curve. Because DIACs are bidirectional devices, their terminals are not labeled as anode and cathode but as A1 and A2 or main terminal MT1 and MT2.

 How to test BT TRIAC Good test with Bad

Today i will show you how to test bt triac easy to understand bt136, bt134 test good transistor with bed transistor, simple and easy electronics projects make at home.

Triac Testing Digital Multimeter. BT136 Triac Test can be triggered by applying either a positive or negative voltage to the gate (an SCR requires a positive voltage). Once triggered, SCRs and TRIACs continue to conduct, even if the gate current ceases, until the main current drops below a certain level called the holding current.

  TRIAC:---

A TRIAC (triode for alternating current; also bidirectional triode thyristor or bilateral triode thyristor[1]) is a three terminal electronic component that conducts current in either direction when triggered. The term TRIAC is a genericized trademark.

TRIACs are a subset of thyristors (analogous to a relay in that a small voltage and current can control a much larger voltage and current) and are related to silicon controlled rectifiers (SCRs). TRIACs differ from SCRs in that they allow current flow in both directions, whereas an SCR can only conduct current in a single direction. Most TRIACs can be triggered by applying either a positive or negative voltage to the gate (an SCR requires a positive voltage). Once triggered, SCRs and TRIACs continue to conduct, even if the gate current ceases, until the main current drops below a certain level called the holding current.

The bidirectionality of TRIACs makes them convenient switches for alternating-current (AC). In addition, applying a trigger at a controlled phase angle of the AC in the main circuit allows control of the average current flowing into a load (phase control). This is commonly used to control the speed of a universal motor, dimming lamps, and controlling electric heaters. TRIACs are bipolar devices.

DIAC:-The DIAC (diode for alternating current) is a diode that conducts electrical current only after its breakover voltage, VBO, has been reached momentarily. Three, four, and five layer structures may be used [1] Behavior is similar to the voltage breakdown of a triac without a gate terminal.

When breakdown occurs, internal positive feedback (impact ionization or two transistor feedback) ensures that the diode enters a region of negative dynamic resistance, leading to a sharp increase in current through the diode and a decrease in the voltage drop across it (typically full switch -on takes a few hundred nanoseconds to microseconds). The diode remains in conduction until the current through it drops below a value characteristic of the device, called the holding current, IH. Below this threshold, the diode switches back to its high-resistance, non-conducting state. This behavior is bi-directional, meaning typically the same for both directions of current.

Most DIACs have a three-layer structure with breakover voltage of approximately 30 V and an on voltage of less than 3 V. Their behavior is analogous to the striking and extinction voltages of a neon lamp, but it can be more repeatable and takes place at a lower voltages.

DIACs are also called "symmetrical trigger diodes" due to the symmetry of their characteristic curve. Because DIACs are bidirectional devices, their terminals are not labeled as anode and cathode but as A1 and A2 or main terminal MT1 and MT2.